Flora of North America species comparison

1–3+ (ridged), erect, branched (usually glabrous proximally, puberulent distally).

1 or 2–5+, erect or prostrate to ascending, branched proximally and/or distally, glabrous or hairy (hairs basifixed and/or medifixed, sometimes stellate).

mainly cauline; petiolate;

blades ovate to rounded-deltate, 4–10+ × 1.5–4 cm, usually 1–2-pinnately lobed (primary lobes 3–5+ pairs, ± ovate), ultimate margins pinnatifid to dentate, faces (at least abaxial) usually puberulent, gland-dotted.

basal and/or cauline; alternate; petiolate or sessile;

blades mostly obovate to spatulate, usually 1–3-pinnately lobed, ultimate margins entire, crenate, or dentate, faces glabrous or hairy.

5–7 mm diam.

mostly hemispheric or broader, (3–)5–22+ mm diam.

flat to conic or hemispheric (sometimes hairy), epaleate.

10–21+ (more in “doubles”), pistillate, fertile;

corollas white, laminae 2–8(–12) mm.

usually 10–21+ (pistillate and fertile or neuter; corollas pale yellow to yellow or white, usually with yellowish bases [pink], laminae oblong to flabellate), sometimes 0 (in disciform or quasi-radiate or -radiant heads, peripheral pistillate florets 8–30+; corollas pale yellow, ± zygomorphic, lobes 3–4, sometimes ± raylike).

ca. 2 mm.

60–300+, bisexual, fertile;

corollas yellow, tubes ± cylindric, throats narrowly funnelform to campanulate, lobes (4–)5, ± deltate.

persistent, (20–)30–60+ in (2–)3–5+ series, distinct, ± ovate to oblong or oblong to lanceolate or lance-linear (sometimes carinate), unequal, margins and apices (pale to dark brown or blackish) scarious (tips sometimes dilated).

5–20(–30) in corymbiform arrays.

usually radiate, sometimes disciform (or quasi-radiate or -radiant), usually in lax to dense, corymbiform arrays, rarely borne singly.

± columnar, 1–2 mm, 5–10-ribbed;

pappi 0 or coroniform, 0.1–0.2+ mm.

obconic or ± columnar (circular in cross section), ribs (4–)5–10(–12+), faces usually gland-dotted, sometimes glabrous (pericarps without myxogenic cells or resin sacs, embryo sac development tetrasporic);

pappi usually coroniform, rarely 0 [distinct scales or each pappus an adaxial auricle].

= 9 (polyploidy).

= 18.